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* [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
@ 2020-08-31  8:02 Jonathan Zhou
  2020-09-07 21:00 ` Will Deacon
  2020-09-08  9:56 ` Suzuki K Poulose
  0 siblings, 2 replies; 7+ messages in thread
From: Jonathan Zhou @ 2020-08-31  8:02 UTC (permalink / raw)
  To: linux-arm-kernel
  Cc: Shaokun Zhang, Catalin Marinas, Will Deacon, Jonathan Zhou,
	Suzuki K Poulose

ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
Self-hosted Trace Extensions. It provides control of exception
levels and security states. Let's add this feature detection and
enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
supported.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
---
 arch/arm64/include/asm/sysreg.h               |  8 ++++++++
 drivers/hwtracing/coresight/coresight-etm4x.c | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 554a7e8ecb07..53da5f326667 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -184,6 +184,13 @@
 
 #define SYS_ZCR_EL1			sys_reg(3, 0, 1, 2, 0)
 
+/* Trace Filter control */
+#define SYS_TRFCR_EL1			sys_reg(3, 0, 1, 2, 1)
+/* Trace is allowed at EL0 */
+#define SYS_TRFCR_EL1_E0TRE		BIT(0)
+/* Trace is allowed at EL1 */
+#define SYS_TRFCR_EL1_E1TRE		BIT(1)
+
 #define SYS_TTBR0_EL1			sys_reg(3, 0, 2, 0, 0)
 #define SYS_TTBR1_EL1			sys_reg(3, 0, 2, 0, 1)
 #define SYS_TCR_EL1			sys_reg(3, 0, 2, 0, 2)
@@ -772,6 +779,7 @@
 #define ID_AA64MMFR2_CNP_SHIFT		0
 
 /* id_aa64dfr0 */
+#define ID_AA64DFR0_SELF_HOSTED_SHIFT	40
 #define ID_AA64DFR0_DOUBLELOCK_SHIFT	36
 #define ID_AA64DFR0_PMSVER_SHIFT	32
 #define ID_AA64DFR0_CTX_CMPS_SHIFT	28
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 96425e818fc2..f72b457c2bad 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -28,6 +28,7 @@
 #include <linux/perf_event.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
+#include <asm/sysreg.h>
 #include <asm/sections.h>
 #include <asm/local.h>
 #include <asm/virt.h>
@@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
 	CS_LOCK(drvdata->base);
 }
 
+static void etm4_init_sysctrl(void *info)
+{
+	u64 sys_trfcr_el1, dfr0;
+	int trace_filt;
+
+	dfr0 = read_sysreg(id_aa64dfr0_el1);
+
+	trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
+					ID_AA64DFR0_SELF_HOSTED_SHIFT);
+	/* if selfhosted trace implemented, enable trace EL0 as default. */
+	if (trace_filt == 0x1) {
+		sys_trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
+		write_sysreg_s(sys_trfcr_el1 | SYS_TRFCR_EL1_E0TRE,
+				SYS_TRFCR_EL1);
+		isb();
+	}
+}
+
 static void etm4_set_default_config(struct etmv4_config *config)
 {
 	/* disable all events tracing */
@@ -1504,6 +1523,10 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 				etm4_init_arch_data,  drvdata, 1))
 		dev_err(dev, "ETM arch init failed\n");
 
+	if (smp_call_function_single(drvdata->cpu,
+				etm4_init_sysctrl, drvdata, 1))
+		dev_err(dev, "ETM sysctrl init failed\n");
+
 	ret = etm4_pm_setup_cpuslocked();
 	cpus_read_unlock();
 
-- 
1.9.1


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^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-08-31  8:02 [PATCH v2] Coresight: etm4x: add support for Self-hosted trace Jonathan Zhou
@ 2020-09-07 21:00 ` Will Deacon
  2020-09-09  6:38   ` Jonathan Zhou
  2020-09-08  9:56 ` Suzuki K Poulose
  1 sibling, 1 reply; 7+ messages in thread
From: Will Deacon @ 2020-09-07 21:00 UTC (permalink / raw)
  To: Jonathan Zhou, mathieu.poirier
  Cc: Shaokun Zhang, Catalin Marinas, linux-arm-kernel, Suzuki K Poulose

[+ Mathieu, since he maintains the driver you're changing]

On Mon, Aug 31, 2020 at 04:02:46PM +0800, Jonathan Zhou wrote:
> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
> Self-hosted Trace Extensions. It provides control of exception
> levels and security states. Let's add this feature detection and
> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
> supported.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
> ---
>  arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>  drivers/hwtracing/coresight/coresight-etm4x.c | 23 +++++++++++++++++++++++
>  2 files changed, 31 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index 554a7e8ecb07..53da5f326667 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -184,6 +184,13 @@
>  
>  #define SYS_ZCR_EL1			sys_reg(3, 0, 1, 2, 0)
>  
> +/* Trace Filter control */
> +#define SYS_TRFCR_EL1			sys_reg(3, 0, 1, 2, 1)
> +/* Trace is allowed at EL0 */
> +#define SYS_TRFCR_EL1_E0TRE		BIT(0)
> +/* Trace is allowed at EL1 */
> +#define SYS_TRFCR_EL1_E1TRE		BIT(1)

Do we also need to make sure we initialise TRFCR_EL2 correctly for the host?

Will

(keeping rest of the patch intact for Mathieu)

> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index 96425e818fc2..f72b457c2bad 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -28,6 +28,7 @@
>  #include <linux/perf_event.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/property.h>
> +#include <asm/sysreg.h>
>  #include <asm/sections.h>
>  #include <asm/local.h>
>  #include <asm/virt.h>
> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>  	CS_LOCK(drvdata->base);
>  }
>  
> +static void etm4_init_sysctrl(void *info)
> +{
> +	u64 sys_trfcr_el1, dfr0;
> +	int trace_filt;
> +
> +	dfr0 = read_sysreg(id_aa64dfr0_el1);
> +
> +	trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
> +					ID_AA64DFR0_SELF_HOSTED_SHIFT);
> +	/* if selfhosted trace implemented, enable trace EL0 as default. */
> +	if (trace_filt == 0x1) {
> +		sys_trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
> +		write_sysreg_s(sys_trfcr_el1 | SYS_TRFCR_EL1_E0TRE,
> +				SYS_TRFCR_EL1);
> +		isb();
> +	}
> +}
> +
>  static void etm4_set_default_config(struct etmv4_config *config)
>  {
>  	/* disable all events tracing */
> @@ -1504,6 +1523,10 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>  				etm4_init_arch_data,  drvdata, 1))
>  		dev_err(dev, "ETM arch init failed\n");
>  
> +	if (smp_call_function_single(drvdata->cpu,
> +				etm4_init_sysctrl, drvdata, 1))
> +		dev_err(dev, "ETM sysctrl init failed\n");
> +
>  	ret = etm4_pm_setup_cpuslocked();
>  	cpus_read_unlock();
>  
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-08-31  8:02 [PATCH v2] Coresight: etm4x: add support for Self-hosted trace Jonathan Zhou
  2020-09-07 21:00 ` Will Deacon
@ 2020-09-08  9:56 ` Suzuki K Poulose
  2020-09-09  7:56   ` Jonathan Zhou
  1 sibling, 1 reply; 7+ messages in thread
From: Suzuki K Poulose @ 2020-09-08  9:56 UTC (permalink / raw)
  To: jonathan.zhouwen, linux-arm-kernel
  Cc: zhangshaokun, catalin.marinas, will, mathieu.poirier

On 08/31/2020 09:02 AM, Jonathan Zhou wrote:
> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
> Self-hosted Trace Extensions. It provides control of exception
> levels and security states. Let's add this feature detection and
> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
> supported.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
> ---
>   arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>   drivers/hwtracing/coresight/coresight-etm4x.c | 23 +++++++++++++++++++++++
>   2 files changed, 31 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index 554a7e8ecb07..53da5f326667 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -184,6 +184,13 @@
>   
>   #define SYS_ZCR_EL1			sys_reg(3, 0, 1, 2, 0)
>   
> +/* Trace Filter control */
> +#define SYS_TRFCR_EL1			sys_reg(3, 0, 1, 2, 1)

> +/* Trace is allowed at EL0 */
> +#define SYS_TRFCR_EL1_E0TRE		BIT(0)
> +/* Trace is allowed at EL1 */
> +#define SYS_TRFCR_EL1_E1TRE		BIT(1)
> +

Please drop SYS suffix for the fields.

>   #define SYS_TTBR0_EL1			sys_reg(3, 0, 2, 0, 0)
>   #define SYS_TTBR1_EL1			sys_reg(3, 0, 2, 0, 1)
>   #define SYS_TCR_EL1			sys_reg(3, 0, 2, 0, 2)
> @@ -772,6 +779,7 @@
>   #define ID_AA64MMFR2_CNP_SHIFT		0
>   
>   /* id_aa64dfr0 */
> +#define ID_AA64DFR0_SELF_HOSTED_SHIFT	40
>   #define ID_AA64DFR0_DOUBLELOCK_SHIFT	36
>   #define ID_AA64DFR0_PMSVER_SHIFT	32
>   #define ID_AA64DFR0_CTX_CMPS_SHIFT	28
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index 96425e818fc2..f72b457c2bad 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -28,6 +28,7 @@
>   #include <linux/perf_event.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/property.h>
> +#include <asm/sysreg.h>
>   #include <asm/sections.h>
>   #include <asm/local.h>
>   #include <asm/virt.h>
> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>   	CS_LOCK(drvdata->base);
>   }
>   
> +static void etm4_init_sysctrl(void *info)
> +{
> +	u64 sys_trfcr_el1, dfr0;
> +	int trace_filt;
> +
> +	dfr0 = read_sysreg(id_aa64dfr0_el1);
> +
> +	trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
> +					ID_AA64DFR0_SELF_HOSTED_SHIFT);
> +	/* if selfhosted trace implemented, enable trace EL0 as default. */

What about EL1 ? We do support kernel tracing. I believe we need to do
this every time when we enable etm4, based on the selected config.


Suzuki

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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-09-07 21:00 ` Will Deacon
@ 2020-09-09  6:38   ` Jonathan Zhou
  0 siblings, 0 replies; 7+ messages in thread
From: Jonathan Zhou @ 2020-09-09  6:38 UTC (permalink / raw)
  To: Will Deacon, mathieu.poirier
  Cc: Shaokun Zhang, Catalin Marinas, linux-arm-kernel, Suzuki K Poulose

Hi Will
Thanks for your review and thanks for adding Mathieu.

On 08/09/2020 05:00, Will Deacon wrote:
> [+ Mathieu, since he maintains the driver you're changing]
> 
> On Mon, Aug 31, 2020 at 04:02:46PM +0800, Jonathan Zhou wrote:
>> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
>> Self-hosted Trace Extensions. It provides control of exception
>> levels and security states. Let's add this feature detection and
>> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
>> supported.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
>> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
>> ---
>>  arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>>  drivers/hwtracing/coresight/coresight-etm4x.c | 23 +++++++++++++++++++++++
>>  2 files changed, 31 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
>> index 554a7e8ecb07..53da5f326667 100644
>> --- a/arch/arm64/include/asm/sysreg.h
>> +++ b/arch/arm64/include/asm/sysreg.h
>> @@ -184,6 +184,13 @@
>>  
>>  #define SYS_ZCR_EL1			sys_reg(3, 0, 1, 2, 0)
>>  
>> +/* Trace Filter control */
>> +#define SYS_TRFCR_EL1			sys_reg(3, 0, 1, 2, 1)
>> +/* Trace is allowed at EL0 */
>> +#define SYS_TRFCR_EL1_E0TRE		BIT(0)
>> +/* Trace is allowed at EL1 */
>> +#define SYS_TRFCR_EL1_E1TRE		BIT(1)
> 
> Do we also need to make sure we initialise TRFCR_EL2 correctly for the host?
> 
As Suziki said in the previous patch[1], accessing TRFCR_EL1 under EL2
will be routed to TRFCR_EL2. I just did a default config in this patch.
Actually, it should be better if we can do this based on the trace
sessions or the kernel config.

[1] https://www.spinics.net/lists/arm-kernel/msg818953.html

Regards
Jonathan

> Will
> 
> (keeping rest of the patch intact for Mathieu)
> 
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
>> index 96425e818fc2..f72b457c2bad 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
>> @@ -28,6 +28,7 @@
>>  #include <linux/perf_event.h>
>>  #include <linux/pm_runtime.h>
>>  #include <linux/property.h>
>> +#include <asm/sysreg.h>
>>  #include <asm/sections.h>
>>  #include <asm/local.h>
>>  #include <asm/virt.h>
>> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>>  	CS_LOCK(drvdata->base);
>>  }
>>  
>> +static void etm4_init_sysctrl(void *info)
>> +{
>> +	u64 sys_trfcr_el1, dfr0;
>> +	int trace_filt;
>> +
>> +	dfr0 = read_sysreg(id_aa64dfr0_el1);
>> +
>> +	trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
>> +					ID_AA64DFR0_SELF_HOSTED_SHIFT);
>> +	/* if selfhosted trace implemented, enable trace EL0 as default. */
>> +	if (trace_filt == 0x1) {
>> +		sys_trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
>> +		write_sysreg_s(sys_trfcr_el1 | SYS_TRFCR_EL1_E0TRE,
>> +				SYS_TRFCR_EL1);
>> +		isb();
>> +	}
>> +}
>> +
>>  static void etm4_set_default_config(struct etmv4_config *config)
>>  {
>>  	/* disable all events tracing */
>> @@ -1504,6 +1523,10 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>>  				etm4_init_arch_data,  drvdata, 1))
>>  		dev_err(dev, "ETM arch init failed\n");
>>  
>> +	if (smp_call_function_single(drvdata->cpu,
>> +				etm4_init_sysctrl, drvdata, 1))
>> +		dev_err(dev, "ETM sysctrl init failed\n");
>> +
>>  	ret = etm4_pm_setup_cpuslocked();
>>  	cpus_read_unlock();
>>  
>> -- 
>> 1.9.1
>>
> .
> 


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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-09-08  9:56 ` Suzuki K Poulose
@ 2020-09-09  7:56   ` Jonathan Zhou
  2020-09-09  9:05     ` Suzuki K Poulose
  0 siblings, 1 reply; 7+ messages in thread
From: Jonathan Zhou @ 2020-09-09  7:56 UTC (permalink / raw)
  To: Suzuki K Poulose, linux-arm-kernel, Mathieu Poirier
  Cc: zhangshaokun, catalin.marinas, will

Hi Suzuki

Thanks for your review.

On 08/09/2020 17:56, Suzuki K Poulose wrote:
> On 08/31/2020 09:02 AM, Jonathan Zhou wrote:
>> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
>> Self-hosted Trace Extensions. It provides control of exception
>> levels and security states. Let's add this feature detection and
>> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
>> supported.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
>> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
>> ---
>>   arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>>   drivers/hwtracing/coresight/coresight-etm4x.c | 23
>> +++++++++++++++++++++++
>>   2 files changed, 31 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/sysreg.h
>> b/arch/arm64/include/asm/sysreg.h
>> index 554a7e8ecb07..53da5f326667 100644
>> --- a/arch/arm64/include/asm/sysreg.h
>> +++ b/arch/arm64/include/asm/sysreg.h
>> @@ -184,6 +184,13 @@
>>     #define SYS_ZCR_EL1            sys_reg(3, 0, 1, 2, 0)
>>   +/* Trace Filter control */
>> +#define SYS_TRFCR_EL1            sys_reg(3, 0, 1, 2, 1)
> 
>> +/* Trace is allowed at EL0 */
>> +#define SYS_TRFCR_EL1_E0TRE        BIT(0)
>> +/* Trace is allowed at EL1 */
>> +#define SYS_TRFCR_EL1_E1TRE        BIT(1)
>> +
> 
> Please drop SYS suffix for the fields.
> 
Thanks, I will fix this.

>>   #define SYS_TTBR0_EL1            sys_reg(3, 0, 2, 0, 0)
>>   #define SYS_TTBR1_EL1            sys_reg(3, 0, 2, 0, 1)
>>   #define SYS_TCR_EL1            sys_reg(3, 0, 2, 0, 2)
>> @@ -772,6 +779,7 @@
>>   #define ID_AA64MMFR2_CNP_SHIFT        0
>>     /* id_aa64dfr0 */
>> +#define ID_AA64DFR0_SELF_HOSTED_SHIFT    40
>>   #define ID_AA64DFR0_DOUBLELOCK_SHIFT    36
>>   #define ID_AA64DFR0_PMSVER_SHIFT    32
>>   #define ID_AA64DFR0_CTX_CMPS_SHIFT    28
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c
>> b/drivers/hwtracing/coresight/coresight-etm4x.c
>> index 96425e818fc2..f72b457c2bad 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
>> @@ -28,6 +28,7 @@
>>   #include <linux/perf_event.h>
>>   #include <linux/pm_runtime.h>
>>   #include <linux/property.h>
>> +#include <asm/sysreg.h>
>>   #include <asm/sections.h>
>>   #include <asm/local.h>
>>   #include <asm/virt.h>
>> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>>       CS_LOCK(drvdata->base);
>>   }
>>   +static void etm4_init_sysctrl(void *info)
>> +{
>> +    u64 sys_trfcr_el1, dfr0;
>> +    int trace_filt;
>> +
>> +    dfr0 = read_sysreg(id_aa64dfr0_el1);
>> +
>> +    trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
>> +                    ID_AA64DFR0_SELF_HOSTED_SHIFT);
>> +    /* if selfhosted trace implemented, enable trace EL0 as default. */
> 
> What about EL1 ? We do support kernel tracing. I believe we need to do
> this every time when we enable etm4, based on the selected config.
> 
I don't know if it's possible to run trace sessions in a guest OS, so I
left the EL1 and EL2 trace disabled. And it's right. We need to provide
an interface to select these configs include the CX and TS feilds of
TRFCR_EL2. How about a sysfs interface?

Regards.
Jonathan.
> 
> Suzuki
> .


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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-09-09  7:56   ` Jonathan Zhou
@ 2020-09-09  9:05     ` Suzuki K Poulose
  2020-09-15 14:43       ` Jonathan Zhou
  0 siblings, 1 reply; 7+ messages in thread
From: Suzuki K Poulose @ 2020-09-09  9:05 UTC (permalink / raw)
  To: jonathan.zhouwen, linux-arm-kernel, mathieu.poirier
  Cc: zhangshaokun, catalin.marinas, will

On 09/09/2020 08:56 AM, Jonathan Zhou wrote:
> Hi Suzuki
> 
> Thanks for your review.
> 
> On 08/09/2020 17:56, Suzuki K Poulose wrote:
>> On 08/31/2020 09:02 AM, Jonathan Zhou wrote:
>>> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
>>> Self-hosted Trace Extensions. It provides control of exception
>>> levels and security states. Let's add this feature detection and
>>> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
>>> supported.
>>>
>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>> Cc: Will Deacon <will@kernel.org>
>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>>> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
>>> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
>>> ---
>>>    arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>>>    drivers/hwtracing/coresight/coresight-etm4x.c | 23
>>> +++++++++++++++++++++++
>>>    2 files changed, 31 insertions(+)
>>>
>>> diff --git a/arch/arm64/include/asm/sysreg.h
>>> b/arch/arm64/include/asm/sysreg.h
>>> index 554a7e8ecb07..53da5f326667 100644
>>> --- a/arch/arm64/include/asm/sysreg.h
>>> +++ b/arch/arm64/include/asm/sysreg.h
>>> @@ -184,6 +184,13 @@
>>>      #define SYS_ZCR_EL1            sys_reg(3, 0, 1, 2, 0)
>>>    +/* Trace Filter control */
>>> +#define SYS_TRFCR_EL1            sys_reg(3, 0, 1, 2, 1)
>>
>>> +/* Trace is allowed at EL0 */
>>> +#define SYS_TRFCR_EL1_E0TRE        BIT(0)
>>> +/* Trace is allowed at EL1 */
>>> +#define SYS_TRFCR_EL1_E1TRE        BIT(1)
>>> +
>>
>> Please drop SYS suffix for the fields.
>>
> Thanks, I will fix this.
> 
>>>    #define SYS_TTBR0_EL1            sys_reg(3, 0, 2, 0, 0)
>>>    #define SYS_TTBR1_EL1            sys_reg(3, 0, 2, 0, 1)
>>>    #define SYS_TCR_EL1            sys_reg(3, 0, 2, 0, 2)
>>> @@ -772,6 +779,7 @@
>>>    #define ID_AA64MMFR2_CNP_SHIFT        0
>>>      /* id_aa64dfr0 */
>>> +#define ID_AA64DFR0_SELF_HOSTED_SHIFT    40
>>>    #define ID_AA64DFR0_DOUBLELOCK_SHIFT    36
>>>    #define ID_AA64DFR0_PMSVER_SHIFT    32
>>>    #define ID_AA64DFR0_CTX_CMPS_SHIFT    28
>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c
>>> b/drivers/hwtracing/coresight/coresight-etm4x.c
>>> index 96425e818fc2..f72b457c2bad 100644
>>> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
>>> @@ -28,6 +28,7 @@
>>>    #include <linux/perf_event.h>
>>>    #include <linux/pm_runtime.h>
>>>    #include <linux/property.h>
>>> +#include <asm/sysreg.h>
>>>    #include <asm/sections.h>
>>>    #include <asm/local.h>
>>>    #include <asm/virt.h>
>>> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>>>        CS_LOCK(drvdata->base);
>>>    }
>>>    +static void etm4_init_sysctrl(void *info)
>>> +{
>>> +    u64 sys_trfcr_el1, dfr0;
>>> +    int trace_filt;
>>> +
>>> +    dfr0 = read_sysreg(id_aa64dfr0_el1);
>>> +
>>> +    trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
>>> +                    ID_AA64DFR0_SELF_HOSTED_SHIFT);
>>> +    /* if selfhosted trace implemented, enable trace EL0 as default. */
>>
>> What about EL1 ? We do support kernel tracing. I believe we need to do
>> this every time when we enable etm4, based on the selected config.
>>
> I don't know if it's possible to run trace sessions in a guest OS, so I
> left the EL1 and EL2 trace disabled. And it's right. We need to provide
> an interface to select these configs include the CX and TS feilds of
> TRFCR_EL2. How about a sysfs interface?

No, you don't need any additional interfaces. The etm4_config should
tell us, if the ETM4 is supposed to filter events for kernel/userspace.
We don't have virtualization support yet, so we could ignore the
TRFCR_EL2, for now.

Either we :

1) Unconditionally enable EL1 & EL0 tracing on each ETMv4 instance
at probe time and leave the trace exclusion by EL to deal with the 
kernel/userspace filtering.

OR

2) For each session of ETMv4 tracing, program the EL1 and EL0 trace
in TRFCR_EL1 based on the exclusion requested by ELs in the configs.

I prefer (1). Also, we must enable CX for TRFCR_EL2, if we are in VHE
to allow contextid tracing.

TS could be set to 0b01 in either case, to use the virtual timestamp.

Suzuki





> 
> Regards.
> Jonathan.
>>
>> Suzuki
>> .
> 


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^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v2] Coresight: etm4x: add support for Self-hosted trace
  2020-09-09  9:05     ` Suzuki K Poulose
@ 2020-09-15 14:43       ` Jonathan Zhou
  0 siblings, 0 replies; 7+ messages in thread
From: Jonathan Zhou @ 2020-09-15 14:43 UTC (permalink / raw)
  To: Suzuki K Poulose, linux-arm-kernel, mathieu.poirier
  Cc: zhangshaokun, catalin.marinas, will

On 09/09/2020 17:05, Suzuki K Poulose wrote:
> On 09/09/2020 08:56 AM, Jonathan Zhou wrote:
>> Hi Suzuki
>>
>> Thanks for your review.
>>
>> On 08/09/2020 17:56, Suzuki K Poulose wrote:
>>> On 08/31/2020 09:02 AM, Jonathan Zhou wrote:
>>>> ARMv8.4 architecture extension introduces ARMv8.4-Trace, Armv8.4
>>>> Self-hosted Trace Extensions. It provides control of exception
>>>> levels and security states. Let's add this feature detection and
>>>> enable E1TRE and E0TRE in TRFCR_EL1 if Self-hosted Trace is
>>>> supported.
>>>>
>>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>>> Cc: Will Deacon <will@kernel.org>
>>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
>>>> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
>>>> ---
>>>>    arch/arm64/include/asm/sysreg.h               |  8 ++++++++
>>>>    drivers/hwtracing/coresight/coresight-etm4x.c | 23
>>>> +++++++++++++++++++++++
>>>>    2 files changed, 31 insertions(+)
>>>>
>>>> diff --git a/arch/arm64/include/asm/sysreg.h
>>>> b/arch/arm64/include/asm/sysreg.h
>>>> index 554a7e8ecb07..53da5f326667 100644
>>>> --- a/arch/arm64/include/asm/sysreg.h
>>>> +++ b/arch/arm64/include/asm/sysreg.h
>>>> @@ -184,6 +184,13 @@
>>>>      #define SYS_ZCR_EL1            sys_reg(3, 0, 1, 2, 0)
>>>>    +/* Trace Filter control */
>>>> +#define SYS_TRFCR_EL1            sys_reg(3, 0, 1, 2, 1)
>>>
>>>> +/* Trace is allowed at EL0 */
>>>> +#define SYS_TRFCR_EL1_E0TRE        BIT(0)
>>>> +/* Trace is allowed at EL1 */
>>>> +#define SYS_TRFCR_EL1_E1TRE        BIT(1)
>>>> +
>>>
>>> Please drop SYS suffix for the fields.
>>>
>> Thanks, I will fix this.
>>
>>>>    #define SYS_TTBR0_EL1            sys_reg(3, 0, 2, 0, 0)
>>>>    #define SYS_TTBR1_EL1            sys_reg(3, 0, 2, 0, 1)
>>>>    #define SYS_TCR_EL1            sys_reg(3, 0, 2, 0, 2)
>>>> @@ -772,6 +779,7 @@
>>>>    #define ID_AA64MMFR2_CNP_SHIFT        0
>>>>      /* id_aa64dfr0 */
>>>> +#define ID_AA64DFR0_SELF_HOSTED_SHIFT    40
>>>>    #define ID_AA64DFR0_DOUBLELOCK_SHIFT    36
>>>>    #define ID_AA64DFR0_PMSVER_SHIFT    32
>>>>    #define ID_AA64DFR0_CTX_CMPS_SHIFT    28
>>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c
>>>> b/drivers/hwtracing/coresight/coresight-etm4x.c
>>>> index 96425e818fc2..f72b457c2bad 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
>>>> @@ -28,6 +28,7 @@
>>>>    #include <linux/perf_event.h>
>>>>    #include <linux/pm_runtime.h>
>>>>    #include <linux/property.h>
>>>> +#include <asm/sysreg.h>
>>>>    #include <asm/sections.h>
>>>>    #include <asm/local.h>
>>>>    #include <asm/virt.h>
>>>> @@ -785,6 +786,24 @@ static void etm4_init_arch_data(void *info)
>>>>        CS_LOCK(drvdata->base);
>>>>    }
>>>>    +static void etm4_init_sysctrl(void *info)
>>>> +{
>>>> +    u64 sys_trfcr_el1, dfr0;
>>>> +    int trace_filt;
>>>> +
>>>> +    dfr0 = read_sysreg(id_aa64dfr0_el1);
>>>> +
>>>> +    trace_filt = cpuid_feature_extract_unsigned_field(dfr0,
>>>> +                    ID_AA64DFR0_SELF_HOSTED_SHIFT);
>>>> +    /* if selfhosted trace implemented, enable trace EL0 as
>>>> default. */
>>>
>>> What about EL1 ? We do support kernel tracing. I believe we need to do
>>> this every time when we enable etm4, based on the selected config.
>>>
>> I don't know if it's possible to run trace sessions in a guest OS, so I
>> left the EL1 and EL2 trace disabled. And it's right. We need to provide
>> an interface to select these configs include the CX and TS feilds of
>> TRFCR_EL2. How about a sysfs interface?
> 
> No, you don't need any additional interfaces. The etm4_config should
> tell us, if the ETM4 is supposed to filter events for kernel/userspace.
> We don't have virtualization support yet, so we could ignore the
> TRFCR_EL2, for now.
> 

Thanks, virtualization is really something out of my mind.

> Either we :
> 
> 1) Unconditionally enable EL1 & EL0 tracing on each ETMv4 instance
> at probe time and leave the trace exclusion by EL to deal with the
> kernel/userspace filtering.
> 
> OR
> 
> 2) For each session of ETMv4 tracing, program the EL1 and EL0 trace
> in TRFCR_EL1 based on the exclusion requested by ELs in the configs.
> 
> I prefer (1). Also, we must enable CX for TRFCR_EL2, if we are in VHE
> to allow contextid tracing.
> 
Yes, (1) seems to be better. Programming TRFCR_ELx based on the ETM
viewinst ELs' configs looks a little strange, for they are filters on
different level. I will apply this in PATCH V3.

Regards.
Jonathan

> TS could be set to 0b01 in either case, to use the virtual timestamp.
> 
> Suzuki
> 
> 
> 
> 
> 
>>
>> Regards.
>> Jonathan.
>>>
>>> Suzuki
>>> .
>>
> 
> .


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^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2020-09-15 14:45 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-31  8:02 [PATCH v2] Coresight: etm4x: add support for Self-hosted trace Jonathan Zhou
2020-09-07 21:00 ` Will Deacon
2020-09-09  6:38   ` Jonathan Zhou
2020-09-08  9:56 ` Suzuki K Poulose
2020-09-09  7:56   ` Jonathan Zhou
2020-09-09  9:05     ` Suzuki K Poulose
2020-09-15 14:43       ` Jonathan Zhou

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